Thursday brought another day of relatively quiet trading on Wall Street, and major market benchmarks finished the day close to unchanged from Wednesday's levels. Investors were upbeat early in the day following a move from the European Central Bank to cut interest rates even further and boost its quantitative easing program, but subsequent comments from ECB President Mario Draghi raised concerns that the central bank has essentially done everything it can to try to stimulate growth. Commodities markets were also relatively flat. However, several stocks posted sharp gains, and U.S. Steel , Flamel Technologies , and Sarepta Therapeutics were among the best performers on Thursday.

U.S. Steel forged ahead 15% as investors continued to buy into the idea of a long-term turnaround for the hard-hit steel market. Macroeconomic concerns in China and other emerging markets have hit steel prices hard for several years, and investors haven't been certain how U.S. Steel would be able to recover from its share-price plunge until conditions in construction and infrastructure began to improve. With new stimulus prospects appearing, prices of commodities like iron ore that are used in steel production have risen sharply, and anticipated demand for steel is on the rise. Already, U.S. Steel stock has doubled just since early February, but if a recovery in heavy construction is here, the stock still has plenty of room to run higher.

Flamel Technologies gained 8% after reporting its fourth-quarter results this morning. The French biopharma stock said its revenue climbed more than 14-fold from last year's fourth quarter, reversing a year-ago loss and producing adjusted net income of $13.9 million for the quarter. CEO Michael Anderson praised the company's achievements during the year, which included positive data on several products and a major marketing license relationship. Looking forward, Flamel believes 2016 could be even stronger, especially after its recent acquisition of FSC Pediatrics and its portfolio of commercial-stage products.

Finally, Sarepta Therapeutics climbed 15%. An independent panel at the FDA will hold discussions on the company's eteplirsen treatment for Duchenne muscular dystrophy on April 25, which investors took as good news despite earlier opinions from FDA staff members expressing doubts about eteplirsen and its potential to improve dystrophin production for patients suffering from the disease. The panel had originally intended to hold its hearing in late January, but a heavy blizzard in Washington, D.C., forced its postponement. Investors hope that without an approved drug to treat the disease, Sarepta's entry will be able to gain approval, and a final decision that incorporates the panel's decision could take place as early as May.